Low power and Lossy Networks (LLNs), e.g., sensor networks, have a myriad of applications, such as Smart Grid and Smart Cities. Various challenges are presented with LLNs, such as lossy links, low bandwidth, battery operation, low memory and/or processing capability, etc. One example routing solution to LLN challenges is a protocol called Routing Protocol for LLNs or “RPL,” which is a distance vector routing protocol that builds a Destination Oriented Directed Acyclic Graph (DODAG) in addition to a set of features to bound control traffic, support local (and slow) repair, etc. The RPL routing protocol provides a flexible method by which each node performs DODAG discovery, construction, and maintenance.
One problem that confronts LLNs is the relative large size of RPL control messages. One reason why RPL control messages are large is because they often contain full IPv6 addresses, which are typically large in size. It is noted that RPL control messages use DAO messages to install downward routes, and in a non-storing mode, the DAO message contains one or more RPL Transit Information Options that indicate the full IPv6 addresses of the DAG parents of the source. To process links having time-varying link qualities, a typical RPL implementation involves having each RPL router maintain multiple DAG parents. Thus, having more parents increases the robustness to any link failures that may occur. Unfortunately, the number of parents directly affects the size of each DAO message. For instance, a RPL control message typically requires 22 bytes for each Transit Information Option (16 bytes of which is attributable to the IPv6 address), which has proven to be large and is disadvantageous since it creates unwanted overhead in communication schemes.